Gauging device for piston rings and other objects



Now 8, 1949 w. F. ALLER ET AL ZAfiFfiZQ GAUGING DEVICE FOR PISTON RINGS AND OTHER OBJECTS Filml Oct 26, 19-45 7' Sheets-Sheet l |NVENTOR5 IMJM BY WM W 7 W ATTORNEY NQV. 8,, 194 w. F. ALLER ETAL, 3 K

GAUGING DEVICE FOR PISTON RINGS AND OTHER OBJECTS Filaci Oct. 26, 1945 7 Sheeis-Sheet z 1 .lllmmli My ENTORS y m Qi/ZWZZ ATTORNEY GAUGING DEVICE FOR PISTON RINGS AND OTHER OBJECTS '7 Sheets-Sheet 3 W. F. ALLER ETAL Nov. 8, 1949 Filed Oct. 26, 1945 hk rggem-om r ATTORNEY Nov. 8, 1949 w. F. ALLER ETAL. 2,487,629

GAUGING DEVICE FOR PISTON RINGS AND QTHER OBJECTS Filed Oct. 26, 1945 7 Sheets-Sheet 4 TRAA/J'FEE mlczzo sW/md' on P was W ATTORNEY Nov. 8, 1949 w. F. ALLER YETHL 2,487,629

GAUGING DEVICE FOR PI STON RINGS AND OTHER OBJECTS Filed 001;. 26, 1945 7 Sheets-Sheet 5 INVENTOR- EAMM ATTORNEY Nov. 8, 1949 w. F.- ALLER ET AL 2,487,629

GAUGING DEVICE FOR PISTON RINGS AND OTHER OBJECTS Filed Oct. 26, 1945 7 Sheets-Sheet e GAUGING DEVICE FOR PISTON RINGS AND OTHER OBJECTS Filed Oct. 26, 1945 7 sheets-sheet 7 R M p w Lana a 011 84/06 /4 wi j/ L090 4; 25.750 0 FLU/V662 40 4 Q y} swam/c120- my. .sMraH-c24e rem s/me-mnem SYV/TCH- 023/ I aging mezzo r 5 Us c247 (i' 45 an 1.55 ma 2&5 27o 315 360 INVENTORJ ATTORNEY Patented Nov. 8, 1949 GAUGING DEVICE FOR PISTON RINGS AND OTHER OBJECTS Willis Fay Allcr and David Ohio, assignors to The Dayton, Ohio, a corporation of Ohio Application October 26, 1945, Serial No. 624,898

7 Claims. (Cl. 88-44) This invention relates to gauging devices and more particularly to devices for measuring or comparing the size or shape of objects.

' One object of the invention is the provision of a gauging apparatus for gauging a circular workpiece, such as a piston ring or the like, and comprising a work holder for receiving the workpiece and adapted for rotation on its own axis, with means for projecting a light beam substantially parallel to the axis of rotation and alon the contacting walls of the workpiece and the work holder, and a light sensitive device to receive the light passing between said walls and control the gauging operation, the device being arranged and constructed for rapidly gauging and selecting a series of workpieces in an automatic and accurate manner.

Another object of the invention is the provision of a gauging device in which piston rings, or the like, are automatically supplied to a gauging station and are automatically moved through the gauging station, with provision for gauging the rings in their course of movement to determine whether or not they conformto a predetermined peripheral shape.

Another object is the provision of a gauging device having a supply position where a series of annular workpieces, such as piston rings, may be stacked one above the other with means for moving the lowest of the rings from the stack and compressing the ring before the ring is moved to a rotatable holder in which the periphery of the ring is gauged.

Another object is the provision of a gauging device having a rotatable holder with cooperating optical means for checking the contour of the ring during rotation of the ring with the holder, the holder being so arranged that as one workpiece is moved into position, in a direction axial of the work holder, the workpiece that was previously in the holder is dropped out of the holder and is received on an inclined trough or track.

H. McConnell, Dayton, Sheifield Corporation,

2 the appended claims, and the accompanying drawing, in which:

Fig. 1 is a perspective view or a gauging device embodying the present invention;

Fig. 2 is an end view of the gauging device, with the end wall removed;

Fig. 3 is a top plan view of the gauging device, a portion of the upper wall of the housing being broken away to show one of the movable track sections;

Fig. 4 is a vertical section on the line 4-4 of Fig- Fig. 5 is a section on the line 5-5 of Fig. 3;

Fig. 6 is a detail showing the stationary abutment plate;

Fig. 7 is a detail showing the feed plate;

Fig. 8 is a section of the abutment plate on line 8-8 of Fig. 6;

Fig. 9 is a section of the feed plate on line 8-8 of Fig. 7;

Fig. 10 is a timing chart showing the time sequence of operations;

Fig. 11 is a perspective view showing a slightly modified form of the invention, where the feed plate compresses the ring against the abutment plate to close the gap in the ring and operates a gauging device which gauges the ring gap before the ring is applied to the rotatable holder;

Fig. 12 is a detail oi the device shown in Fig. 11, showing the yielding connection between the feed plate and its operating arm;

Fig. '13 is a wiring diagram showing the electrical connections and corresponding to the form of invention shown in Fig. 11, the timing chart of Fig. 10 also corresponding to this same arrangement;

Fig. 14 is a wiring diagram corresponding to the modification of the invention shown in Fig.v

l, in which the piston'ring gap is gauged during the rotation of the ring with the holder;

Fig. 15 is a timing chart corresponding to Fig. 14; and

Fig. 16 is a diagrammatic view showing the path of light beams in the modification corresponding to Figs. 10, 11 and 12.

Referring more particularly to the drawing, Figs. 1 to 9 inclusive show one form of the invention in its adaptation for checking piston rings although obviously the invention can be adapted for checking other workpieces. In the particular form shown, however, the device comprises a main housing structure Ill providing a platform II with a fixed cross-plate I2 bolted in place. Guide strips l3 fixed on the platform and underlying the cross-plate I! serve to guide a reciprocating feed plate H which is automatically moved back and forth by a suitable motor drive, as shall be presently explained. Rising from the cross-plate l2 are retainer posts I5. A stack of workpieces, such as piston rings, one of which is shown at l6, may be placed on the feed plate I4 between the three spaced posts IS. The apparatus may then be set in motion by energizing the drive motors, and the rings are then automatically supplied, from the bottom of the stack to a point above a rotatable gauging ring or work holder where they are compressed. They are then forced downwardly into the work holder which has a diameter corresponding to the size of the cylinder in which the rings are intended to operate. The work holder then rotates the ring, optical means being provided so that a light beam is squeezed or compressed until its diameter is a predetermined value, the shape of the cam being such that the feed plate is moved to properly compress the piston ring at the end of the feed movement of the plate. In the position of the parts shown in Fig. 1, .the feed plate l4 has been moved part way towards the compression position, one ring 16 being in position where compressing starts, leaving the ring that was above it free to descend to rest on the upper surface 34 of the feed plate.

After the piston ring is compressed it is forced downwardly into the rotatable gauging ring or work holder, as will be presently described, and the feed plate returns to the retracted position shown in Fig. 3 so that the stack of rings again descends until the lowermost ring of the stack is passed between the outer surface of the workpiece and the inner surface of the gauging ring or work holder if the fit between the piston ring and the work holder does not conform to the desired standard. The light is received by a light responsive device which controls gauging and selecting devices that determine the path the gauged ring takes when it leaves the work holder so that those rings that satisfy the required standard automatically move to one receiver and the rings that fail to pass the required gauging test automatically move to another receiver. Still another path of movement is provided for those rings that fail to meet the gauging test on the length of the ring gap when the ring is compressed to the same extent that would prevail while in a piston of the proper size, this gauging of the ring gap also being carried out, in the form of apparatus illustrated in Figs. 1 to 9. during the rotation of the workpiece with the work holder.

As shown more particularly in Figs. 1 and 4, the feed plate. I4 is moved back and forth by a motor l8 which drives a cam shaft I 9 having cams 20 and 2| which respectively operate the arms 22 and 23 of a lever 24 pivotally supported at.24' on a portion of the frame structure. The cam 20 serves to rock the lever 24 clockwise as viewed in Fig. 4, while the cam 2| moves the lever counter-clockwise. The upper end of the lever 24 is connected by a link 25 to the bracket .26 fixed on the lower side of the feed plate l4.

The feed plate l4, as shown in Figs. S and '7,

, cooperates with a fixed abutment plate 28 to compress the ring after the ring has been moved from the bottom of the stack of rings. The abutment plate 28 is of segmental form, having a cylindrical abutment surface 29 with a radius of curvature substantially the same as the cylinder in which the ring is intended to operate. The feed plate l4 also has an arcuate surface 30, and when the feed plate is moved to its ring compressing position, the piston ring will be compressed between the two surfaces 29 and 30to substantially the diameter of the cylinder in which the ring will operate. The plate I4 is provided with a ledge 32 and shoulders 33 extending between the upper surface of this ledge 32 and the upper surface of the plate indicated at 34. The ledge 32 supports the lower side of the piston ring as the ring is moved from the supply position to the compression position, and the'shoulders 33, where they contact the piston ring, move the expanded ring forward as the plate moves. The ledge 32 is received in a recess 35 inthe abutment plate 28 when the two plates are closed together. As the feed plate closes against the fixed abutment plate, the workpiece rests on the ledge 32 and on a small fixed supporting bar or projection 31 carried by the lower side of the centrally arranged post 15 (see Fig. 1). The feed plate 44 is provided with a groove 33 to receive the bar 31.

After the ring is compressed by the feed plate in conjunction with the abutment plate, as previously described. it is moved axially downwardly by a plunger 39 carrying a spider 40 having fingers provided with radial rollers 4|. These rollers contact the upper surface of the compressed piston ring and move the ring bodily downwardly from between the abutment and feed plates and into the rotatable work holder or gauging ring 42. The plunger 39 is moved at the proper time by means of a lever 43 pivoted at 44 and moved by a drive link 45 (see Figs. 1 and 4). The lower end of the drive link is pivotally connected to a rock lever 46 controlled by another cam on the cam shaft IS. A spring 41 moves the drive link 45 upwardly as permitted by the cam drive for lever 46, to normally maintain the spider 40 spaced above the path of the feed plate, and as shown in Fig. 4.

The work holder 42, as shown in Fig. 5, is an annular member having a cylindrical gaug ng surface 49, of limited axial extent and adapted for contact with the peripheral surface of the piston ring. The ring I6 is shown in Fig. 5 in the position to which it is forced by the spider 40 when that member reaches the limit of its downward travel. Above the gauging surface 49, the inner surface of the gauging ring is preferably slightly bevelled and there is a bevel providing a conical surface 50 below the cylindrical surface 49, so that as another ring is moved into position by the spider 40 it will force the ring which 'is already in the gauge ring downwardly and'the tension exerted by the ring on the conical surface 50 will cause the ejected ring to continue its downwardly movement and fall into an inclined trough or track 5|.

The gauge ring 42 is continuously rotated by a motor 52 which drives a pinion 53. The pinion meshes with gear teeth on a gear ring 54 fixed on the lower side of the gauging ring 42. A series of three rollers 56 pivotally carried on the supporting frame engage the lower side of the gauging ring 42 and serves to support it and the gear ring 54. Additional rollers 51 rotatable on vertical axes engage the periphery of the ring 42 and definitely locate the axis of the ring with respect to the supporting frame. As the piston ring is rotated with the gauging ring, the periphery or contour check is made, and a sizing operation is carried out to determine whether or not the ring gap is too large or too small or falls within the required tolerance.

Arranged on a mounting bracket 58 is a lamp 60 which projects a beam of light vertically downwardly through a lens BI and through a groove 62 in the abutment plate 23 and then through a hole 63 which is provided in the track or trough (see Figs. 3, 4). Arranged below the hole 63 is a light responsive relay 2|! shown in Fig. 5 and in the wiring diagram Fig. 14, and if sufiicient light passes between the periphery of the piston ring and the cylindrical surface 48 of the gauging ring 42 to cause the light responsive relay to respond, it will select or energize a suitable relay mechanism that will be described so that a portion or section of the track or trough will be moved when the gauged ring moves down the trough. Those rings that satisfy the tolerance requirements of the gauging operation, when ejected from the gauging ring 42, travel along the track 5| and fall onto a collecting or receiving post 64 at the rear of the apparatus. Those rings that fail to pass the periphery check, permitting the passage of too much light between the piston ring periphery and the inner surface of the gauging ring 42, will start down the trough but will be laterally deflected because of the upward movement of the track section 65 pivotally carried at 66 and controlled by a solenoid 61 under the control of the periphery gauging light responsive element. A similar track section 68 (see Fig. 4) remains in its normal position as shown in that figure to support the other side of the descending piston ring, assuming the gap distance of that ring conforms to the required tolerance dimensions. With no support for one side of the ring, due to the lifting of the track section 65, that side drops, the center ridge I59 below the track receiving the lowered center portion of the gauged ring which is thus so tilted laterally that it descends through the lateral trough and falls onto the collecting post H (see Fig. 2). If the gap does not conform to the desired size, the gap gauging device causes energization of a solenoid to lift the track section 68 on its pivotal support 12 so that the ring will be tilted laterally and will descend through the trough 13 and be collected on the collecting post 14.

In this embodiment of the invention the gap distance is gauged during the rotation of the workpiece with the gauging ring 42, the gauging operation being carried out by the light beams projected downwardly from two lamps 16, one of which is shown in Fig. 4. Below each of these lamps is a lens 11 which projects beams downwardly past grooves 18 in the abutment plate 28 and through holes 19 and 80 in the trough 5i (see Fig. 3). Arranged in line with the light beams passing through the holes 19 and 80 and below those holes are two light responsive devices or tubes 2 and 2I3, see Fig. 14, one to see if the gap is too large and the other to see if the gap is too small. When the piston ring gap comes in line with the light beam to the tube 2, if the gap is undersize there will be an' insufiicient energization of the tube to fire or energize it and it will not conduct current to set the relay or gauging circuit. If the gap is within tolerance or too large the tube 2 will be'energized and operate the gauging circuit. Light coming to the tube 2I3 will effect the control of the gauging circuits if the gap is too large, but if the gap is undersize or of a predetermined proper range of size, this tube will not effect the gauging circuits which will remain in their normal positions.

To prevent the passage of light to the light 6 sensitive tube that checks the peripheral contour of the piston ring, at the instant the gap moves past that tube, a solenoid I90 (see Fig. 5) is energized. This energization, which is controlled by an electric circuit affected by an auxiliary light beam passing through the gap from the lamp to to the tube 2 III takes place just before the ring gap passes the periphery checking tube and the energization of solenoid I30 continues until the gap has passed. This solenoid I30, when energized, rocks a lever I9I to project a slide or shutter I92 to the left to the position as viewed in Fig. 5. There are holes in this shutter that normally permit the passage of light beams to the tubes 2, 2I2, and 2I3, but when the shutter is projected, as mentioned, light is blocked from the tube 2I2 and from the tubes 2 and 2I3.

In the form of the invention shown in Fig. 11, the ring gap is gauged as an incident to its movement to the gauging ring, the construction of this form of the device corresponding to the form of construction shown in Figs. 1 to 9 except as will be particularly pointed out. As shown in Fig. 11, the feed plate I is provided with a lug IBI which comes up into engagement with a auging plunger 99 substantially at the end of its feed stroke. The

movement of the feed plate I80, instead of being positive and of a fixed definite length of stroke, is efiected through a yielding drive so that the feed plate continues to move to compress the piston ring until its gap is entirely closed. The drive link 25 shown in Fig. 4 is thus replaced by the drive link 25' illustrated in Fig. 12. This drive link is made in two sections 92 and 93 and a rather strong compression spring 94 normally holds the two sections together but permits the link to lengthen when the motion of the feed plate is stopped by the closed piston ring during the continued forward feed movement of the lever arm 24. The drive link 25 is of such length that the slide I80 will move far enough to compress piston rings and completely close th gaps even though the gaps are oversize.

When the piston ring gap is closed by the joint action of the feed slide I80 and the abutment plate I84, and before the spider I35 moves down- -wardly to push the piston ring into the rotatable gauging ring, the extent of movement of the feed slide is determined to gauge the piston ring gap. This is accomplished by gauging switches Ill and I13 controlled by the gauge plunger 99. The switches HI and I13 may be operated by the gauging plunger 99 in the manner disclosed in Patent 2,384,519, granted September 11, 1945. The two switches HI and I13 will both be closed when the piston ring gap is within the required tolerance limits. If the gap is too small the slide I80 will not travel quite as far and the switch I13 will be open. If the gap is too large, the switch ill will open. These switches control the gauging and selecting circuits as will be more fully described.

After the gap of the ring is gauged, the spider I forces it down into the rotatable holder or gauging ring and the periphery check'is made during its rotation in that ring. For this purpose the lamp I21 provides a light beam that travels 'past the inside of the gauging ring and the outer periphery of the piston ring. If the fit of the ring permits the passage of light sufilcient to energize the light responsive device in line with this beam a gauging circuit is effective on a selecting circuit. A shutter is provided that blocks off the passage of light when the gap itself is passing by this main beam, the shutter being operated by e, circuit which is controlled by light reflected from a mirror I32 and traveling at an angle through the gap just before the sap reaches the main beam as will be more fully explained.

As to a more complete description of the operation of the construction shown in Fig. 11, I23 in Fig. 13 designates a suitable supply source connected to the primary winding I2I of a transformer. The secondary windings I22 of the transformer are connected to rectifier tubes I23 supplying rectified current at a positive potential to point I24 and a negative potential to a point I25. I26 is the light responsive relay or tube, such as a No. 930 tube, that is arranged directly below the light source or lamp I21. This lamp is connected through wire I29 to a transformer secondary I33 so that it will remain energized during the gauging operations. Light beams emitted from the lamp I21 and transmitted by the reflector I32 pass at an angle to the vertical through the gap in the ring, when the gap comes into-the line of the beam, and are received by the second light responsive device I33, preferably another No. 930 tube.

If suificient light passes from the lamp I21 to the tube I26 'to make that tube conduct current, as in case of a poor ring contour, the grid potential of a relay tube I35 will be affected. The grid of this tube I35 is connected through a potentiometer circuit I36 to a relay tube I31 such as a VR-90 tube that maintains a constant bias voltage to the grid'of the tube I35 and also to the grid of a similar tube I33 having a grid connected to the tube I33 in a similar manner. A tube I4I similar to the tube I31 is provided to maintain a stabilized supply of current of constant voltage to the lead I42 connected to both the tubes I26 and I33. Normally the tube I35 has no substantial flow of current in its plate circuit as its grid potentiaLJWith respect to its cathode, is such that it will not conduct current. When this grid potential is changed sufficiently by energizing the tube I26, a current flow takes place through the plate circuit I33 energizing a winding I40 then through a normally closed switch I6Ia and back to the point I24 of positive potential. I43 designates a filter circuit connected to winding I43. When light is received by the tube I33, at a time just prior to the time the ring gap passes the beam from the lamp I21 to the tube I26, then energization of this tube I33 provides current flow from the plate of the tube I38 through a winding I 52, then through a, switch I58a closed during motor operation by energization of a winding I53 during motor operation, and back to one side of the transformer primary I2I, the other side being connected to ground at I 3I Connected across the winding I52 is a condenser I54 which keeps the relay coil energized some small time after current flow ceases from the plate of I 33 due to the stoppa e of light supply to the tube I33. This time is suflicient to keep the coil I52 energized until the piston ring gap has passed the beam from lamp I21 to tube I26 so that the periphery checking light beam will not energize tub I26 when the gap passes.

\ Connected tothe supply source I23 are lead wires I55 and I56. A motor switch I51 can be closed to supply current to the motors I3 and 52, and when the switch I51 is closed a current flow takes place through the winding I53 closing the switch I53a previously mentioned and closing a normally open switch I53b which is arranged in series with a cam controlled microswitch CI60 operated from the cam shaft I3. The

in series with two holding switches "51; and I614.

Switch IBM is connected in series with and controlled by a winding I65. A green lamp I33 is preferably connected across this winding. Switch I'61a is arranged in series with and controlled by a winding I61 having a red lamp I63 connected across it. When either of the coils I65 or I61 are energized, their respective lamp bulbs will be lighted and a holding circuit will be completed through their respective switches I65a and I61a. The coil I66 is connected through wire I63 to a normally open switch I14a then through a switch "I to the wire I55. The coil I61 is connected through a normally open switch "41; then through switch I13 to the wire I 55. Switches I14a and I14b are both closed when a coil I14 is energized by closing a microswitch CI15 which is automatically operated by the cam shaft I3 as indicated opposite "gap timer switch in Fig. 10. If the switches I13 and HI are both closed when the gap timer microswitch CI15 closes, circuits will be completed through both coils I65 and I61, energizing both the red and green lamps I63 and I66 for visual indication and then after the switch CI15 opens again circuits will be maintained through these coils I65 and I61 through the switches I65a and I61a and the closed switch I6Ia until that switch IIiIa is later opened to interrupt the gauging circuit.

The two switches HI and I13 are operated by the gauging plunger 33 controlled by the feed slide of the machine and both of these switches will be closed when the piston ring gap is within the required tolerance. If the piston ring gap is too large and the feed slide moves over farther than it should, it opens the switch I1I. If the ring gap is too small, the feed slide will not travel far enough to close the switch I13. If either of these two switches are open at the time of the gauging operation there will be no current flow through their respective coils I65 and I61.

When one or the other of the two coils I65 and I61 is energized, due to the failure of the piston ring being gauged to comply with the required gap tolerance, the coil that is energized will open one or the other of two switches I65!) and I61b whichever it controls. I13 are closed because the rin gap size is satisfactory, both coils I65 and I61 will be energized and their respective switches I65!) and I61b will be open, and therefore the rejection coil I13 cannot be energized. The two switches I651; and I312) are connected in parallel from the lead wire I55 through a cam controlled microswitch CI11 which effects the transfer of the setting of the gauging circuit relays I65 and I61 at the proper time, as shown in Fig. 10, over to the selecting circuit in which the switches I65b and I6") are arranged. If either of these two switches are closed, a circuit will be completed through a winding I13 which will close a switch I13a, and after passing through winding I13 the current travels through a normally closed peripheral checking switch H311 to the other sideof the line I56. The switch I4Ila is controlled or opened when the coil I43 is energized due to sufllcient light traveling from the lamp I21 to the peripheral checking light If both switches HI and sensitive device I26 so that if the periphery does not satisfy the required standard, the switch 011 will render the gap rejecting circuit inoperative and the periphery gauging circuit will take precedence. However, assuming the periphery satislies the required standard and the coil I40 is not energized, then the coil I18 will be energized if the gap is either too large or too small as previously mentioned, and at the same time the rejection solenoid that controls one side of the track or trough will be energized to lift that section of the track and cause the lateral travel of the gauged piston rin to the receiver 14. The circuit from closed switch Ia through the solenoid 15 will be completed through the switch I18a held closed by energized winding I18 to connect the solenoid directly to the wire I until the reset microswitch CI82, which is normally closed, is momentarily opened to normalize the rejection solenoid 15. The switch CI82 is controlled by a cam on the cam shaft II! as indicated in Fig. 10.

If the periphery of the piston ring does not conform to the required standards and the light passage to the tube I26 is then sufficient to cause current flow to the plate of tube I35, to coil I40, the energization of that coil will close a normally open switch I401: connected in series with a coil I84 and a microswitch C I which is controlled by the cam shaft I9 with the same timing as the microswitch CI11. Energization of the coil I84 closes the switch I84a connected to one side of the line I55 and to the periphery rejection track lifting solenoid 61 to lift the track section 66 and cause lateral movement of the gauged piston ring to the receiver H. A switch I841), closed when the coil I84 is energized, connects the rejection solenoid I51 to the lead wire I56 even though switch M01) is subsequently opened, and maintains current flow through the rejection solenoid 61 until the microswitch CI82 opens later in the cycle for resetting the selection circuit.

The lead wire I56 is also connected through a shutter controlling solenoid I in series with the microswitch CI9| controlled by a cam on the cam shaft I9 to temporarily close during the time the piston ring is being loaded into the rotating gauging ring 42 so that the passage of light during that time past the periphery of one or both of the piston rings in the rotatable gauging ring 42 will not effect energization of the tube I26. The shutter controlling solenoid I90 is also connected from one'side of the line to the other through the switch I52a closed by winding I52 when that winding is energized due to the light flow to tube I38 at the time the piston ring gap permits such light passage. Conenser I54 maintains a temporary energization of the coil I52 to prevent light passage through the gap when the gap passes the beam to the periphery checking tube or light responsive device I26.

Current supplied to the entire gauging circuit and the selecting circuit is interrupted by opening switch I580 which is controlled by the relay coil I58, when the motor switch I51 is opened and the coil I58 is de-energized.

As will now be apparent, the gauge head con- 'taining the switches HI and I13 set up the gauging circuit in accordance with whether or not the ring gap is too large or too small or conforms to the required tolerance condition and the gauging circuit is maintained even after the actual gauging time is past. The setting of the gauging circuit is transferred to the selecting circuit because that is effective later in the cycle and to permit the gauging circuit to be then normalized so that the next ring will be gauged while the selecting circuit for the previously gauged ring is effective to control the course of the ejected ring along the track. Those rings that pass the required standard for both periphery shape and ring gap will travel straight down the track since neither of the track lifting rejecting solenoids 61 nor 15 will be energized. If the ring periphery does not conform to the required standard, the solenoid 61 will be energized, regardless of the size of the ring gap. If the periphery is satisfactory but the ring gap is too large or too small, the other side of the track will be lifted by solenoid 15 to select just those rings having an improper gap size for collection on the post 14.

Fig. 14 shows the wiring connections and Fig. 15 the timing chart particularly applicable to the embodiment of the invention illustrated by Figs. 1 to 9 inclusive, where the ring gap is checked during the rotation of the piston ring with the gauging ring 42. The operation of the various selecting and gauging circuits is some what similar to the operation of the construction illustrated in Figs. 11 and 13. The lamps 16 and 60 are connected to the secondary of a transformer 2I5 supplied from a power source 2I6. A

transformer 2 I1 supplies current to rectifier tubes 2I8. Another transformer 2I9 supplies current to another rectifier tube 220. These tubes are connected to the voltage regulating relay tubes 22I and 222, preferably VR-90 tubes. The cathodes of the light responsive tubes 2I0 and 2I3 inclusive, which are preferably 930 tubes. are connected to the control tubes 223, 224, 225 and 226 respectively, these being preferably 2050 tubes.

If sufflcient light is passed from the light source 60 to the tube 2I2 to cause sufficient energization of the grid 221 of the tube 225, current will flow from the plate of that tube to the relay winding 228, which closes switches 228a and 22%. The latter energizes a red lamp 230, while the switch 228a serves to complete a circuit, when a cam controlled switch 023i is closed, through the solenoid 232 that controls the rejection of the piston ring by operating one side of the track along which the ring slides after it has moved from the gauging ring. This switch also energizes a solenoid 233 which closes switch 233a, and the energization of the relay 232 will then be maintained, once the switch C23I closes, until the circuit is interrupted later in the cycle by a cam operated switch shown at C241.

If the piston ring has a gap that is too small there will not be enough light passing from the lamp 16 to the tube 2I3 to energize the grid of the tube 226 sufficiently to make that tube conduct current and consequently the relay 235 connected to this plate circuit will not be energized. Relay 235 controls switches 235a and 2351). The switch 235a will thus remain closed and the switch 23% will remain open. Closed switch 235a, energizes a relay 236 controlling the normally open switch 236a. The latter maintains current through the gap rejection solenoid 231 which elevates the other side of the track to divert the checked piston ring from its straightthrough path along the slide. Energized relay 236 also controls normally closed switch 236a and normally open switch 236b, connected respectively to yellow and green lamps 238 and 239.

If the gap in the ring is of normal size or 9V?! Size, sufficient voltage will be supplied to 11 the'grid of the tube 226 to cause a current flow through the relay 235 and change the switches 235a and 235b, de-energizing the relay 236 so that the gap rejection solenoid 231 will not Operate. However, if the gap is too large, when it comes opposite the tube 2 there will be sufficient energization of that tube to energize the control tube 224 so that current flow will take place through the relay winding 240. This relay controls switches 240a, 2401) and 2400. Switch be will be closed if the gap is oversize, closing a circuit through switch 235!) which had previously been closed, then relay 236, thus closing switch 236a and energizing the gap rejection solenoid 231.

Just before the gap comes in line with the light responsive tube 2l2, a beam reflected from the mirror adjacent the lamp 6!! passes through the gap to the tube 2ft, energizing tube 223 so that the current flows through the relay winding 2.

This winding, when energized, closes a switch 24M in circuit with solenoid I90 that controls the shutter so as to temporarily block of! light from the periphery gauging lamp.

The timing of the operations corresponding to Fig. 14 are shown in Fig. 15. Cam operated switches C246, C241, C248, and the switch C23l previously mentioned are connected in the various circuits to produce the proper timing sequence so that the selection circuits will be set up by the gauging circuits, permitting the gauging circuits to be then normalized so thatlthe next ring will be gauged while the selecting circuit for the previously gauged ring is efiective to control its course along the track. Switch C246 when closed energizes winding 250 which opens switches 250a and 250?). Those rings that pass the required standards for both periphery shape and ring gap will travel straight down-the track since neither of the track lifting rejection solenoids will be energized.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to those precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. An apparatus for gauging a circular workpiece such as a piston ring, comprising a support, having means for holding a stack of the workpieces, a work holder rotatably mounted on said support at one side of the stack holding means and adapted for telescopic engagement with the workpiece, a slide reciprocally operable on said support for moving the workpieces one at a'time from the bottom of the stack to a loading position adjacent the work holder, means operable in timed relation to the slide movements for moving a workpiece from the loading position to the work holder, means for projecting a light beam substantially parallel to the axis of rotation and along contacting walls of the workpiece and work holder, a light sensitive device for receiving light passing between said walls, and gauging means controlled by said light sensitive device for gauging the periphery of the workpiece.

2. An apparatus for gauging a circular workplace such as a piston ring, comprising a support,

a work holder rotatably mounted on said support and adapted for telescopic engagement with the workpiece, a motor having a driving connection with said workholder to rotate the work holder about its own axis, a plunger mounted for reciprocal movement on said support in line with the work holder for supplying a workpiece to the work holder through one end thereof while the work holder remains on the support, drive means for operating said plunger in timed relation to said driving connection, said work holder having a limited area for engagement with the workpiece and said supplying means having a predetermined limit of movement whereby the supply of a new workpiece forces the workpiece in the work holder outwardly through the other end thereof, means for projecting a light beam substantially parallel to the axis of rotation and along the contacting walls of the workpiece and work holder, a light sensitive device for receiving light passing between said walls, and gauging means controlled by said light sensitive device.

3. An apparatus for gauging a circular workpiece such as a piston ring, comprising a support, a work holder rotatably mounted on said support and having a cylindrical ring receiving surface, means for projecting a light beam along said cylindrical surface, a light sensitive device for receiving light passing between said surface and the ring, gauging means controlled by said light sensitive device for gauging the peripheral form of the workpiece, power means for rotating said work holder, a slide slidably mounted on said support for feeding the workpieces successively from a supply station at one side of the work holder in a direction transverse of the work holder axis and into alignment'with the cylindrical surface of the work holder and immediately adjacent the work holder, and a plunger reciprocally mounted on said support concentrically with said cylindrical surface to automatically supply a workpiece to the workholder during rotation of the work holder, and means for operating said plunger in timed relation to said slide.

4. An apparatus for gauging a circular workpiece such as a piston ring comprising a support, a work holder rotatably mounted on said support and having a cylindrical ring receiving surface,

means for projecting a light beam along said cylindrical surface, a light sensitive device for receiving light passing between said surface and the ring, gauging means controlled by said light sensitive device, power means for rotating said Work holder, an abutment on said support having a segmental surface adjacent and in line with a portion of the cylindrical ring receiving surface of said work holder, a feed plate operably mounted on said support for moving a ring against said abutment, said feed plate having a segmental portion cooperating with the segmental portion of the abutment to compress the piston ring in a location in line with the cylindrical ring receiving surface of the work holder, means for moving said feed plate towards and from the abutment, and means for supplyin the compressed ring from the feed plate and abutment to said work holder.

5. An apparatus for gauging a circular workpiece having a gap between its ends, comprising a support, a work holder rotatably mounted on said support and having a circular wall to receive the workpiece, means for projecting a light beam along said wall between the wall and the workpiece, a light sensitive device for receiving light passing between the workpiece and the wall, gauging means controlled by said light sensitive device for showing an abnormal contour of the workpiece, means operably mounted on said support for supplying workpieces in a direction at an angle to the axis of rotation of the work holder to a point closely adjacent to the work holder and for compressing the workpiece in a position in line with the circular wall of the work holder to close the gap in the workpiece, gauging means operated by said supplying and compressing means in accordance with the extreme position it attains in the compressing movement for gauging the closed outside diameter of the workpiece, means for moving the workpiece from the supplying and compressing means to the work holder, and. means for operating said supplying means and said moving means in timed relation with the rotational movement of the workholder.

6. An apparatus for gauging a circular workpiece such as a piston ring, comprising a, support, a work holder rotatably mounted on said support and having a cylindrical wall for-receiving the workpiece, an abutment fixed on said support. adjacent said work holder having an arcuate wall adjacent the work holder for cooperation with one side of the workpiece, a feed plate operably mounted on said support and having an arcuate wall cooperating with the abutment and movable toward said abutment to compress the ring so the gap closes, means for gauging the extent of travel of the feed plate to thereby gauge the ring gap, means for supplying the ring from between the ieed plate and abutment into said work holder, and means for gauging the periph- 14 eral contour of the ring during its rotation in the work holder.

7. An apparatus for gauging a circular workpiece as set forth in claim 1 said work holder having a limited area for contact with the workpiece positioned therein and so that a new workpiece supplied to the work holder forces the one in the work holder outwardly therefrom.

WILLIS FAY ALLER. DAVID H. MCCONNELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 888,772 Wilkinson May 26, 1908 1,204,026 Johnson Nov. 7, 1916 1,306,744 Brenzinger June 17, 1919 1,310,837 Murch July 22, 1919 1,611,441 Higgins Dec. 21, 1926 1,618,965 Herrmann Feb. 22, 1927 2,138,645 Rey Nov. 29, 1938 2,177,133 Desch Oct. 24, 1939 2,433,558 Hurley Dec. 30, 1947 2,441,343 Becker May 11, 1948 2,448,314 Kavanagh Aug. 31, 1948 

